I think it’s an interesting idea, but it’s just a concept right? And it’s intended for public sector use, rather than consumer use.
Average people who want to try a European Linux distro on their home computer could try Ubuntu (British) or OpenSUSE (German). Or whatever you like really. Debian is not really European but it is a global FOSS project so you could use that if you want.
My Linux experience is mainly with Debian and Ubuntu so I’m biased towards those I guess. Use what you like though.
They do those things to some degree, but those things remain banned for under 18s, which I suppose reduces harm, even if it doesn’t fully eliminate harm.